show Abstracthide AbstractcDNA was prepared from mRNA from five life cycle stages (larva, pupa, worker, male and gyne) and a total of 1,610,742 expressed sequence tags (ESTs) were generated using Roche 454 technology, increasing the sequence data available for this important species 50-fold. Overlapping ESTs were assembled into 36,354 Bombus terrestris putative transcripts, and functionally annotated. To prepare the samples: Total RNA was extracted from each whole bodied Bombus terrestris specimen. cDNA was synthesised using the SMART approach by the Evrogen synthesis service, Russia. First strand cDNA was synthesised using reverse transcriptase (RT) from a 3'-primer with oligo(dT) sequence that annealed to the poly-A stretch of RNA and synthesised cDNA until the 5' end of the mRNA. Finally, double stranded cDNA synthesis was performed using PCR amplification, and the final product contains the Evrogen SMART Oligo II and CDS primer at 3' and 5' ends. The cDNA was fragmented, size-selected, library-prepped, and sequenced according to standard Roche-454 Titanium protocols.